sorting - Caching sortable/filterable data in Redis -


i have variety of data i've got cached in standard redis hashmap, , i've run situation need respond client requests ordering , filtering. order rankings name, average rating, , number of reviews can change regularly (multiple times minute, possibly). can advise me on proper strategy attacking problem? consider following example understand i'm looking for:

  1. client makes api request /api/v1/cookbooks?orderby=name&limit=20&offset=0
  2. i should respond first 20 entries, ordered name

strategies i've considered far:

  • for each type of hashmap store (cookbooks, recipes, etc), creating sorted set each ordering scheme (alphabetical, average rating, etc) postgres order by; pulling out zrange slices based on limit , offset
  • storing ordering data directly json string data each key.
  • hitting postgres select id table order _, , using ids pull directly hashmap store

any additional thoughts or advice on how best address issue? in advance.

so, mentioned in comment below sorted sets great way implement sorting , filtering functionality in cache. take following example idea of how 1 might solve issue of needing order objects in hash:

  1. given hash called "movies" scheme of bucket:objectid -> object, json string representation (read "bucketing" hashes performance here.

  2. create sorted set called "movieratings", each member objectid "movies" hash, , score average of rating values (computed database). use numerical representation of whatever you're trying sort, , redis gives lot of flexibility on how can extract slices need.

  3. this simple scheme has lot of flexibility in can achieved - ask sorted set set of keys fit requirements, , keys hmget "movies" hash. 2 swift redis calls, problem solved.

  4. rinse , repeat whatever type of ordering need, such "number of reviews", "alphabetically", "actor count", etc. filtering can done in manner, normal sets quite sufficient purpose.


Comments

Post a Comment

Popular posts from this blog

SPSS keyboard combination alters encoding -

my question not have programming practical issue on spss. accident keyword combination cannot remember because did not intend press changed encoding in spss , text in data in different language english shown small boxes. nevertheless, when kind of analysis performed different language text shown in output. does know reason? tried change encoding did not produce result. first, @ edit > options , see whether setting unicode or locale. might fix it. if have text in multiple languages, want unicode. otherwise, may have specific locale set wrong. can change set locale, need know locale want use.
Read more

Add new record to the table by click on the button in Microsoft Access -

in ms access form want implement separate button, adds new record table. in order added button , attached button event: private sub btnaddrec_click() refresh codecontextobject on error resume next docmd.gotorecord , , acnewrec if err.number <> 0 btnaddrec.enabled = false end if end end sub everything ok when open window , click btnaddrec button, problem when first of perform navigation through existed records , after click on button. got runtime error: 2105: «you can't go specified record. may @ end of recordset» . how solve issue, need have ability add new record on click on specific button, no matter, have walked or not walked through records before. thanks. i created simple form field call description (and autonumber) , created button code follows click event. filled number of records , navigated through them, clicked addnewrec button. form navigated new record without issues. able click addnewrec button directly after ...
Read more

Socket.connect doesn't throw exception in Android -

if put nonsense url no exception thrown , none of rest of code executed not rest of asynctask called method connects. try { socketcliente.connect(new inetsocketaddress("f", port), 2000); } catch (unknownhostexception e) { geterror("host doesn't exist"); return -1; } catch (ioexception e) { geterror("could not connect: host down"); return -1; } add catch statement. catch ( exception e ) { log.d(tag, e.getmessage(),e); toast.maketext(getapplicationcontext(), "unexpected error:" + e.getmessage(), toast.length_long).show(); } this write log , pop toast tell what's going on.
Read more